Table 3.

Concentrations of selected potentially harmful elements and their descriptive statistics in Winam Gulf and Lake Victoria sediments

	Ag	Al	As	Cd	Cr	Cu	Fe	Ni	Pb	Sn	Zn	Hg
SQG
TEC	–	–	9.79	0.99	43.4	31.6	–	22.7	35.8	–	121	0.18
PEC	–	–	33	4.98	111	149	–	48.6	128	–	459	1.06
U.S. EPA
ERL	1.0	–	8.2	1.2	81	34	–	20.9	46.7	–	150	0.15
ERM	3.7	–	70	9.6	370	270	–	51.6	218	–	410	0.71
North
Mean	0.25	84,508	3.5	0.26	63	50	63,633	35	24	4.5	165	0.05
SD	0.18	16,488	1.4	0.08	29	27	18,862	10	11	1.7	52	0.03
Max	1.1	108,996	5.4	0.52	247	131	125,118	50	86	6.9	262	0.17
Min	0.20	37,076	0.2	0.03	32	1.4	5351	6.1	6.6	0.18	7.0	0.002
South
Mean	0.24	78,034	5.6	0.32	63	39	85,626	40	34	4.8	201	0.03
SD	0.06	18,566	2.8	0.12	22	22	51,057	19	20	1.6	99	0.02
Max	0.47	131,692	13	0.57	109	77	254,282	74	105	8.6	466	0.05
Min	0.20	40,073	0.5	0.08	25	3.8	24,351	7.0	12	0.8	37	0.002
Straits
Mean	0.23	72,887	2.8	0.25	88	74	83,688	39	20	3.8	173	0.04
SD	0.05	13,171	0.9	0.06	81	24	15,006	12	5.0	0.5	32	0.01
Max	0.36	85,223	4.2	0.35	386	121	132,332	88	36	4.8	255	0.06
Min	0.20	31,159	0.3	0.09	39	22	52,369	27	9.2	2.5	65	0.004
Lake
Mean	0.20	62,091	3.6	0.20	71	66	78,915	34	17	3.3	145	0.07
SD	0.00	11,194	1.2	0.06	37	22	14,978	2.0	2.9	0.3	15	0.02
Max	0.20	72,549	4.7	0.30	167	109	108,051	37	23	3.7	165	0.10
Min	0.20	37,062	0.9	0.12	44	40	52,048	30	13	2.8	118	0.03

All values are in mg kg⁻¹. Samples are measured as dry weight using sediment quality guidelines from MacDonald (2000) PEC—probable effect concentration, and TEC—threshold effects concentration and the US EPA (US EPA, 1999, 2002), ERL—effects range low, ERM—effects range media. Mean values greater than the effect range low (ERL) are highlighted in bold. SD ± 1 standard deviation